Rookes v Barnard  UKHL 1
Douglas Rookes was a draughtsman, employed by British Overseas Airways Corporation (BOAC). He resigned from his union, the Association of Engineering and Shipbuilding Draughtsman (AESD), after a disagreement. BOAC and AESD had a closed shop agreement, and AESD threatened a strike unless Rookes resigned also from his job or was fired. BOAC suspended Rookes and, after some months, dismissed him with one week’s salary in lieu of proper notice.
Rookes sued the union officials, including Mr Barnard, the branch chairman (also the divisional organiser Mr Silverthorne and the shop steward Mr Fistal). Rookes said that he was the victim of a tortious intimidation that had used unlawful means to induce BOAC to terminate his contract. The strike was alleged to be the unlawful means.
At first instance, before Sachs J, the action succeeded. This was overturned in the Court of Appeal. The House of Lords reversed the court of appeal, finding in favour of Rookes and against the union. Citing a case from the eighteenth century called Tarelton v. M’Gawley (1793) Peake 270 where a ship fired a cannonball across the bows of another, Lord Reid said the union was guilty of the tort of intimidation. It was unlawful intimidation ‘to use a threat to break their contracts with their employer as a weapon to make him do something which he was legally entitled to do but which they knew would cause loss to the plaintiff.’ 
A corollary to the main issue in the case, but of greater lasting importance, was Lord Devlin ‘s pronouncements on when punitive damages are applied. The only three situations in which damages are allowed to be punitive, i.e. with the purpose of punishing the wrongdoer rather than aiming simply to compensate the claimant, are in cases of,
1. Oppressive, arbitrary or unconstitutional actions by the servants of government.
2. Where the defendant’s conduct was ‘calculated’ to make a profit for himself.
3. Where a statute expressly authorises the same.
This aspect of Rookes v Barnard has not been followed in Canada , New Zealand or Australia . 
The case was met with immediate outrage for creating, or reviving, economic torts as a weapon to undermine the right to strike. This was reversed by the Trade Disputes Act 1965 .